Latch structure for door locks



Nov. 19, 1957 E- L. SCHLAGE 2,813,740

LATCH STRUCTURE FOR DOOR LOCKS 2 Sheets-Sheet 1 Filed May 20, 1955 v INVENTOR. ERNEST L. SCHLAGE Nov. 19, 1957 E. L. SCHLAGE 2,813,740

LATCH STRUCTURE FOR DOOR LOCKS Filed May 20, 1955 2 Sheets-Sheet 2 FIG. 5

INVENTOR. ERNEST L. SCHLAGE 030326 )IFMV 2,813,740 LATCH STRUCTURE FOR noon LOCKS Ernest L. Schlage, Burlingame, Calif., assignor to Schlage Lock Company, a corporation Application May 20, 1955, Serial No. 509,829

2 Claims. or. 292-169 This invention relates to door locks and especially that type in which assembly or removal of the lock from a door is controlled by overdepression or retraction of the latch bolt.

In Patent No. 2,207,877, a door lock is disclosed in which assembly or removal of the lock from a door is controlled by overdepression of the latch bolt. The lock briefly stated comprises a housing having a retractor with a connected latch bolt slidably mounted therein, and a pair of spindles whereby the retractor and latch bolt are actuated, also the lock contains a dogging mechanism which normally secures the spindles against removal, but

which releases the spindles when overdepression of the latch bolt takes place. The mechanism employed is simple and efficient, but there is one objection, and that is that a special tool is required to release the depressible latch before overdepression of the latch bolt can take place.

-The object of the present invention is to provide a door lock in which assembly or removal of the lock from the door is controlled by overdepression of the latch secondary spring it becomes possible to do away with the depressible latch and the special tool requiredin 'the structure of Patent No. 2,207,877, also it simplifies construction and by preloading the secondary spring accidental or mischievous overdepression of the latch bolt-is prevented, as preloading of the spring requires the application of considerable pressure to the end of the latch bolt before overdepression can take place.

The invention is shown by way of illustration in the. accompanying drawings, in which:

Fig. l is a vertical longitudinal section of a door lock mounted in a door and showing thelatch bolt in normal projected position; p

Fig. 2 is a similar view showing a latchbolt in normal retracted position;

Fig. 3 is a similar view showinga latch bolt in overdepressed position; 1

Fig. 4 is a horizontal longitudinal section taken on line IVIV of Fig. 1, but showing certain elements in elevation;

Fig. 5 is a perspective view of one form of retractor;

Fig. 6 is a perspective view of the inner end of one of the spindles;

Fig. 7 is a perspective view of the latch bolt guiding member; and,

Fig. 8 is a perspective view of the plate which supports the inner ends of the spindles.

Referring to the drawings in detail and particularly Figs. 1 to 4, A indicates a portion of a door in whichls drilled or bored two holes, one through the edge of the door as indicated at B and the other transversely of the door as indicated at C. The lock housing indicated at 2 is inserted through the hole B and its inward movement is limited by a face plate 3 which is secured in place by screws 4. In the outer end of the housing and normally projecting through the face plate is a latch bolt 5 which is secured to a slidably mounted latch bolt guiding memher 6. This guide is U-shaped, see Fig. 7, and straddles a stationary plate 7 disposed crosswise of the housing and fixed thereto, this plate together with the housing forming a support and guide for the latch bolt guiding memjected position.

Adjacent the inner end of the housing is slidably mount-v ed a retractor (Fig. 5). The retractor is also U-shaped and consists of two spaced apart side sections 9-9 and a connecting end section 10. The side sections each have an opening formed therein, the forward portion of each opening being rounded as at 42 and the rear portion of each opening presenting a straight vertical face 11, which is acted upon by the rollback members of the spindles as will hereinafter be described. The portions of the side sections of the retractor behind the vertical faces 11 will hereinafter be referred to as detents 12 as they interlock with the respective spindles to secure them against removal at all times except when the latch bolt is overdepressed for the purpose of releasing the spindles during assembly or removal of the lock from the door. 1

The lock structure here described shows two spindles, but a single spindle, or a telescoping type of divided spin dle such as shown in Patent No. 2,207,877 may be 'em-f:

ployed. The spindles here illustrated are of the tubular type, see Fig. 6, and are indicated by the numeral 16.

The inner end of each spindle is cut away as indicated at 13 to form a pair of shoulders 1414, and outwardly,

but adjacent the rollback members are formed slots 15' which are provided for reception of the interlock detents 12 previously referred to and to form rollback members 15a. The outer ends of the spindles are provided with knobs (not shown) which may be secured thereon in any suitable manner.

With the spindles in place (Fig. 4) the detents 12 ente'r the slots 15 of the respective spindles and interlock with Y the spindles and secure them against endwise removal. If a spindle is rotated in the direction of arrow a (Fig. 2') one rollback member 15a will engage the vertical face 11 of the retractor and force it rearwardly to a position where the latch bolt assumes normal retracted position (Fig. 2); On the other hand, if manual pressure is applied to the end of the latch bolt and it is overdepressedas shown a in Fig. 3, the retractor will be forced further toward the rear of the housing or to a position where the detents 12 are fully retracted with relation to the slots 15, and

when that position is assumed as shown in Fig. 3, both spindles are free and may be removed by pulling them outwardly from the housing. Similarly, if the spindles are to be inserted during assemblyor installation ofithely lock, "the latch bolt will have to beoverdepressed in order Patented Nov. 19, 1957 v while" projection of the latch bolt is actuated by the constant pressure exerted by the main spring 8. The guide member which carries the latch bolt is in some instances directly connected to the retractor, so asto move in. unison with thesame. In the structure here shown, a motion multiplying lever 17 is interposed. This lever is pivoted at 20' to the rear end of the latch bolt guide, thus, if the motion imparted to the retractor'by the rollback members of the spindles is one quarter of'an inch the motionof thelatch bolt and its guide member will be one half inch, as the lower pivot 18 ofthe lever is-stationary, and the leverage'istwo to one.

The plate is fixedly secured in the housing midway between the side walls of the housing, and in alignment with the axis of the spindles. This plate serves a number'of important functions. First of all, it is straddled by the retractor and in conjunction with the housing forms a guide therefor. upon which the motion multiplying lever is pivoted as at 18. Third, it will be noted by referring to Figs. 4, 8, that a boss 23 is formed on each side thereof. These bosses receive and form bearings for the inner ends of the spindles, and finally, the anchor plate carries a stop lug 24 (Fig. 8) which limits rotational movement of the spindles. The stop lug 24 is important as overrotation of'the spindles could otherwise take place with the result that they would free themselves of the detents and could then be removed. In use, overrotation is prevented by engagement of shoulders 14 with lug 24. The detailedconstruction of the lock housing, the plate 25, the retractor, the motion multiplying lever and the latch bolt guide,

etc.,' are fully illustrated and described in my copending. application entitled Bearing and Spindle Structure forv in Figs. 1 to 3. Referring to Fig. 1, it will be noted that the cross ,plate 7 supports a pin having a head at each endasindicated at 32 and 33. A spring 31 which may be; termed a secondary spring surrounds the ,pin and is interposed between the plate 7 and the head 32 of the pin...

During normal operation of the latch bolt, the secondary spring is inactive, but it manual pressure is applied to the. end of the latch bolt and it is overdepressed as shown in;

Fig. 3;the, end 6:: of the latch bolt guide engages the head 32 ofthe pin 30 and as the pin is freely slidable in the plate 7, spring 31 becomes compressed; This spring may be preloaded to. such an extent that while manualdepressionof the latch bolt from the position shown in; Fig. l to the position shown in Fig. 2 may be accomplished. with comparatively little resistance, the pressure is instantly andvery considerably increased the moment overdepression commences, as spring 31 may be preloaded to any pressure increase required. For instance,

children will often amuse themselves by turning the knobsof the door and pushing on the end of the latch bolt, but

their 'strength'willusually not be sufficient to overdepress. the latch bolt asin Fig. 3, dueto the greater pressure- Secondly, it carries the extension arm required to compress the preloaded spring 31, on the other hand;-'if*the"secondary-spring were-not provided,'a child might readily overdepress and at the same time holding on to a knob might accidently pull it and the spindle out of the lock, hence a preloaded secondary spring will prevent playing or mischievous children from removing the knobs and spindles. A mature person or a mechanic will have no trouble as they have the strength to compress spring 3L, and,fur.thermore,,willjnot require a special tool during assembling or removal.

While the secondary spring isshown as supported and carried by the cross plate 7, it might just as well be carried by-thexreanendplate 10. of the. retractor, asshown at 40 in Fig. 5. In that position, it would ,beinactive during normal projection and retraction of the latch bolt. If overdepression takes place as in Fig. 3 the head end 41 of the pin would engage the inner end of the housing and thepreloaded springwould be compressed and resist overdepression in the same manner as shown in Fig.3.

I claim:.

1. In a door lock structure having a housing and a latch bolt reciprocable therein from a projected position projecting outwardly from such door to a depressed position withdrawn into'said door and adapted to be further depressed toan overdepressed position, a latch bolt spring 7 urging said latch bolt'to said projected position at all times andarr auxiliary spring positioned outwardly of said. spindle applying a substantially greater force to said latchbolt than saidlatch bolt spring and adapted to be compressed upon movement-of said latch bolt from said depressed. to said overdepressed position for resisting such movement; aretractor--mechanism and a spindle operativeiygconnected-to saidmechanism,- interengaging elements onsaidspindle and mechanism for holding them inoperating relationship, and said elements being disengageable when said latch bolt is in said overdepressed position:

2. In -a door lock structure having a housing and a latch bolt 'reciprocable therein from a projected position projecting outwardly from such door to a depressed position withdrawn intosaid door and adapted to be further depressed to an overdepressedposition, a latch bolt spring urging said latch bolt to said projected position at all times and an auxiliary spring positioned outwardly of said spindle applying'a substantially greater force to said latch bolt than said-latch bolt spring .and adapted to be compressed upon movement of said latch bolt from said depressed to said overdepressed position for resisting such movement, a retractor mechanism and a spindle operatively connected to said mechanism, interengaging elementson said spindle and mechanism for holding them in operating relationship, and said elements being disengageable when-said latch bolt is in said overdepressed position, an'axially extending pin mounted for reciprocation and-acting as a retainer for said auxiliary spring, said latch bolt spring being mounted concentric with said auxiliary bolt: spring;

References Cited. in the fileof this patent UNITEDSTATES" PATENTS 1,759,375 Schlage May 20, 1930 2,062,766 Schlage Dec. 1, 1936 2,207,877 Schlage, July 16, 1940 2,302,380- Schlage Nov. 17, 1942. 2,330,011 Schlage Sept. 21, 1943 

